The Red Rock Oklahoma
Tornado April 26, 1991

The spring of 1991 was loaded with tornado events and April 26th
produced some of the most violent. It was a busy chase day. I witnessed an
impressive supercell that produced 2 funnels that were almost tornadoes. The
second of the two
funnels came close the
ground near the Oklahoma - Kansas border. It later developed a huge rotating
mesocyclone that produced the Windfield, Kansas tornado. Due to road problems I
let the storm go before the tornado formed. Dropping south into Oklahoma I
intercepted a supercell that produced the so called Red Rock, OK tornado shown
here. After that I proceeded south and east to observe a large tornado crossing
the Cimarron Turnpike southeast of Stillwater, OK. Cars drove into the tornado
while it crossed the 4-lane causing one fatality. I later witnessed the same
storm produce a huge tornado with a one mile wide damage path north of Tulsa.
It moved through sections of Skiatook and nearby Collinsville silhouetted by green
power line flashes and continious lightning. It continued to the northeast developing into a large
wedge until out of sight very near the town of Oologah where heavy damage
was reported.

Facts about the tornado in the following images: It moved from near
Garber, OK to near the town of Pawhuska, OK for a path length of 66 miles. A
University of Oklahoma chase team used a portable doppler radar to measure wind
speeds of 286 MPH. This wind speed is usually associated with F-5 tornadoes,
but F-4 damage was the worst found and that's where the tornado was rated. The
tornado destroyed a couple of homes and farms and was responsible for six
injuries. Fortunately it traveled across rural areas with low population
density.

The first image depicts a forming tornado about 2 miles west of
the camera position in a circling rain curtain. The second image shows the
bottom of the funnel as it nears a farm. A light debris circulation may be seen
below and trailing behind the funnel.

This set shows the tornado moving across the farm. Large
sections of sheet metal were seen spinning through the air toward cloud base.
The rain in the near vicinity of the tornado was decreasing allowing better
visibility.

A more established debris cloud was beginning to spin up as the
condensation funnel neared the ground. In the second image the debris cloud
caught up with the tornado and became larger.

The tornado continued to move east, but did not plant a
condensation funnel on the ground. A strong circulation persisted under the
funnel. At this point the damage track as measured immediately after crossing
the nearby road was 4/10 of a mile wide. This was measured by my vehicle
odometer. The width of this path was quite shocking after seeing only a narrow
point of the tornado above the ground.

In a dramatic escape the two occupants of the auto bailed out
and took shelter in a nearby drainage ditch. The edge of the vortex crossed
their position. They were unhurt. Trees and power poles just north of their
position were downed.

In this image the tornado finally sent a condensation funnel to
ground. The debris cloud remained much larger than the visible funnel.

Looking like a classic tornado the base of the funnel whips
around with suction spots circling the outer edge. The tornado was beginning to
grow larger. From this point it will grow into a large white cone then a dark
dusty wedge as it crosses interstate 35.

Go to Red Rock Part II for the
tornado images east of I-35 as it grew to 3/4's of a mile wide.